The Montana Supreme Court on Wednesday reversed the conviction of a Beaverhead County man for criminal distribution of dangerous drugs, saying he was convicted based on insufficient evidence.

The court ruled in a 4-1 decision that state prosecutors presented the testimony of just one witness, who said Anthony James Burwell provided her with marijuana in exchange for baby-sitting his two daughters while he went to work in summer 2011.

Jennifer Jones told authorities that the night before she was supposed to baby-sit, she and Burwell smoked a bowl of a substance she said was marijuana, describing it as "green with orange hairs," according to the opinion written by Chief Justice Mike McGrath.

Jones identified Burwell in a list of "people to narc on" that she wrote while in police custody, McGrath wrote. She gave a vague description of the man and said he lived next door to her friend, according to the opinion.

Officers concluded Jones was referring to Burwell, found that he had a medical marijuana card and charged him in October 2011. He was convicted in district court and sentenced to 10 years, with five years suspended.

"Officers never searched Burwell's residence, never attempted a controlled buy and never discovered any marijuana in his possession," McGrath wrote.

No expert analyzed Jones' description of the substance, no other witnesses backed her testimony and she did not describe the effects of the substance, McGrath wrote.

The evidence was insufficient to conclude beyond a reasonable doubt that the substance was a dangerous drug, the chief justice wrote.

Justice Jim Rice dissented, saying that the majority opinion ignores significant circumstantial evidence and that it was up to the jury that convicted Burwell to determine the facts.

Burwell acknowledged that he did not pay Jones cash for baby-sitting and that Burwell and his son were medical marijuana cardholders permitted to grow the drug at home, Rice wrote.

"The testimony here, of a lay witness identifying marijuana from prior experience with the drug, along with the confirming circumstantial evidence, is sufficient to establish the identity of the substance," Rice wrote.